Electro-mechanical serial printers



Nov. 28, 1967 G. HAAS 3,354,818

ELECTRO-MECHANI CAL SERIAL PRINTERS Filed Oct. 14, 1965 5 Sheets-Sheet l INVENTOR. GE RHA RD HA A S Nov. 28, 1967 G. HAAS 3,354,818

ELECTRO-MECHANICAL SERIAL PRINTERS Filed on. 14, 1965 5 t -Sheet 2.

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INVENTOR. GERHARD HAAS G. HAAS ELECTRO-MECHANICAL SERIAL PRINTERS Nov. 28, 1967 Filed Oct. 14, 1965 5 Sheets-Sheet 5 INVENTOR. GE RHA RD HA A 8 G. HAAS Nov. 28, 1967 ELEGTRO-MECHANI CAL SERIAL PRINTERS 5 Sheets-Sheet 4 Filed Oct. 14, 1965 Nkk INVENTOR. GERHARD HAAS Nov. 28, 1967 G. HAAS ELEC'TRO-MECHANICAL SERIAL PRINTERS 5 Sheets-Sheet 5' Filed Oct. 14, 1965 GERHARD HAAS M cglvr 7 United States Patent M 3,354,818 ELECTRO-MECHANICAL SERIAL PRINTERS Gerhard Haas, Hamburg, Germany, assignor to North American Philips Company, Inc., New York, N.Y., a

corporation of Delaware Filed Oct. 14, 1965, Ser. No. 496,037 Claims priority, application Germany, Oct. 16, 1964,

4 Claims. 61. 101-93 ABSTRACT OF THE DHSCLOSURE With various simple ofiice calculating machines, for example balancing machines, 3- or 4-operation machines, and registering cash machines and also to other recording apparatus such as recording measuring instruments the problem exists of printing the results at a low cost. The printers commonly used in mechanical machines may be made at a low cost and while these printers have an appropriate printing speed they cannot be adapted for electronic equipment without extensive modification. In .the simple electronic otlice calculating machines the number to be printed is, in most cases, stored in a storage system consisting of counters andconstructed in the form of a shift register. The known mechanical printers are poorly .adapted to such a storage, which means that the coupling between the electronic computing member .and the mechanical printer is difiicult to achieve. Accordingly, it has heretofore been the practice to utilize printers which provide an overall cheaper method of printing electronically obtained computing results despite the sometimes higher cost of the printer proper.

For example, electro-magnetic printers operating on the principle of high-speed printers have been used for this purpose.

' In such printers the ink carrier and the paper are arranged between the continuously or stepwise rotating type cylinder, the periphery of which has a set of characters for each place to be printed, and a group of magnetically operated hammers, that is to say one for each place. Printing of a line is carried out so that first, for example, all noughts, then all 1s and so on are printed in parallel. This principle is not satisfactory for simple ofiice machines because the attainable speed of printing is much higher than is required for these simple uses, and because a magnet has to be controlled and energized for each place to be printed.

Furthermore there are known printers comprising only one hammer, which is advanced along the line so that the separate places are printed in order of succession. For each place the hammer is actuated at that instant at which the desired character is located opposite the hammer. In view of the discontinuously moving large mass this print- .ing method is too slow.

The invention relates to an electro-mechanical serial printer having a rotating type cylinder and magnetically controllable hammers. The material to be printed is moved stepwise between the hammers. Between the type v cylinder and a stationary magnet there is arranged a con 3,354,813 Patented Nov. 28, 1967 tinuously movable hammer carrier, the structure of which is such that in order of succession each time one hammer for the separate place gets in between the type cylinder and the magnet, the latter is energized when the desired sign is located opposite the hammer.

The novel serial printer has the advantage that only one magnet need be controlled, so that space and electronic apparatus can be economized, such a printer being therefore suitable for simple printing machines.

The drawing shows a few embodiments.

FIG. 1 shows a printer comprising a disc operating as the hammer carrier.

FIG. 2 shows a printer comprising a hammer carrier in the form of a tape.

FIG. 3 shows a printer comprising a cylindrical hammer carrier.

FIG. 4 is a diagrammatic plan view of the disc-shaped hammer carrier.

FIG. 5 is a developed view of the type cylinder allowing scanning in the horizontal direction.

FIG. 6 shows diagrammatically the circuitry of the electronic control suitable for use in horizontal scanning of the type cylinder.

FIG. 7 shows a further embodiment of the electronic circuitry suitable for vertical scanning of the type cylinder.

The printer shown in FIG. 1 comprises, a type cylinder T, a disc H, operating as a hammer carrier and having, for each place of the type cylinder, a hammer h the hammers being arranged along a helical line (see hammers I1 h h 11 it I11 FIG. 4). The hammer disc H and the type cylinder T move with uniform speed and are coupled through a worm wheel transmission G so that the axes of rotation are at right angles to each other. The separate hammers h are disposed so that each time after 21r/s-revolutions of H the next-following hammer arrives in front of the next-following place of the type cylinder.

The ink tape F and the paper to be printed P are arranged between the type cylinder T and the hammer disc H. Behind the hammer disc is located the printing magnetM the armature of which E has approximately the height of the characters and the width of the type cylinder. The hammer disc is constructed so that only one hammer h can be struck at one time by the armature. The type cylinder T is provided on its periphery with a set of signs for each place to be printed. The paper driving member is formed by the two pressure rollers R and R and the electro-magnet M which turns the rollers R at each pulse through the angle defined by the line space. The hammers disc H and the type cylinder are each rigidly connected with a control-disc S and S respectively, which provide for example by photoelectric scanning, the-required synchronizing signals, which will be explained more fully hereinafter.

Instead of a disc the hammer carrier may be an endless tape or a rotating drum. When the hammer carrier consists of a tape, the printing magnet M is located in side the tape i.e. inside tape K (FIG. 2) and in the case of the drum it is located inside the drum Z (FIG. 3). The hammers h themselves are mounted in this instance, on small springs f at the periphery of the drum in a helical array so that during the uniform rotation of the drum the separate places of the type cylinder T are covered in order of succession.

According to the invention two methods of operation are possible in the embodiments shown in FIGS. 1 and 3, that is to say: vertical and horizontal scanning of the information to be printed; in the embodiment shown in FIG. 2 only horizontal scanning is possible. The two scanning modes will be described more fully with reference to the embodiment of the printer shown in FIG. 1.

In horizontal scanning of the information to be printed the places of a line are covered once for each sign of the type cylinder T. For each place the type cylinder comprises a set of B signs and L voids, the paper being displaced to the next-following line during the voids. In horizontal scanning first for sample all 9s, then all 8s" etc. of the line are printed in order of succession. Since in one revolution of the hammer disc H all places are covered, the hammer disc has to turn a number of times equal to the sum of the number of signs and the number of voids, whereas the type cylinder performs at the same time one revolution. This requires a reducing transmission between the motor-driven hammer disc and the type cylinder. After one revolution of the hammer disc H the type cylinder T has turned through an angle (,0. The separate signs of the type cylinder must have shifted through said angle (p (FIG.

Since synchronisation fluctuation will occur between the place where the hammers and the armature E come into contact with each other, the hammers are not accurately struck at the correct place. To compensate for lack of accuracy, the hammers may be constructed in the form of circular members, that is, having a circular striking area.

The highest sequential frequency of the printing magnet occurs when the same signs are to be printed at adjacent places. The control-disc S supplies a pulse for each hammer and hence for each place of the line. The controldisc S as is shown in FIG. 6, has two slots L and L marking the beginning and the end of printing. The slot L is associated with the first sign to be printed and the slot L with the last sign to be printed. In the space between L and L which corresponds to the voids of the type cylinder, the paper is shifted. The accurate location of the slots is suchthat the signal P supplied by the lightsensitive member F coincides with the signal P supplied by the light-sensitive member F corresponding to the first place to be printed. The signal of the slot L is located closely after the signal P of the last place.

The operation of the, printer will be explained with reference to FIG. 6 for a numerical printer with places. The type cylinder T and the hammer disc H are continuously driven by the motor M. In the rest position the bistable trigger FFl cuts off the gate U so that the pulses P remain ineffective. The bistable trigger FFZ is also in the zero position so that p pulses, intended to reset FFZ to the initial position, have no effect. The zero position of FFZ cuts off the gates U and U so that neither the 1 pulses in an accumulator A of an arithmetic member or the like nor the carry pulses p produced at the accumulator place a (during the arithmetic operation) can become operative. The printing order p passed through I renders FFI operative. The next-following p pulse, which coincides with the p pulse of the first place, can pass through the gate U and sets F1 2 so that the gates U and U are opened. A pulse from the slot L in F cannot pass U since it does not coincide with a 2 pulse. At this instant the digit 9 is in front of the paper and the hammer h, in front of the first place. As soon as the hammer has reached the first place, the front flank of the associated p pulse raises the content of the first storage place a by 1. If at a a 9 was present, the resultant carry through the gate U subsequent to amplification in V renders the printing magnet M operative, so that at the first place the digit 9 is printed. Thereupon the rear flank of 7 supplies the shift pulse for the storage so that the second place is then at a As soon as the hammer has reached the second place on the type cylinder, the F5 pulse raises again the content of a by 1. If also the second place is a 9, printing is again performed, etc.

After one revolution of H the content of the storage A has turned once and all places have been raised by 1. At the same time the 8 is ready for being printed on the type cylinder T. During the next-following turn of H all required (which have in the meantime been raised 9s) are printed. After the tenth turn of H, all digits of the line have been printed, after which the storage has again the initial content. The light-sensitive member F supplies the final pulse p which resets FFZ to Zero. The resultant output pulse rests FFl and subsequent to amplification in V it actuates the magnet M for the paper transport to the next-following line. If in the meantime FFI is actuated by a new printing order, p causes printing of the next-following line, while in the other case no printing is effected.

With a printing speed of, for example, two lines per second of 10 places each, the maximum sequential frequency of the printing magnet is about 220 c./s.

In the vertical scanning of the information to be printed the type cylinder T covers each place before the hammer disc H has turned to the next-following place. The type cylinder has at its periphery a set of signs for each place. Apart from the hammers the hammer disc has voids, the paper being displaced when the latter are covered. For printing one line the type cylinder must perform a number of revolutions equal to the sum of the number hammers and of voids.

The separate hammers h;, 11 I1 h, of the hammer disc must have circular faces in order to cover the separate places until the set of signs has passed by. Since the printing magnet must engage each time only one hammer, printing must not be effected during the transition from a hammer h to the hammer h The maximum sequential frequency of the printing magnet occurs when the last or the first sign has to be printed at adjacent places. Then the printing interval corresponds to the L voids. A great number of Voids requires great accuracy in synchronisation, but on the other hand a low maximum printing frequency.

The operation of the last-mentioned printer will now be described with reference to a numerical printer having 10 places (FIG. 7). The control-disc S has a slot L by which the shift pulses P3 are supplied and for each of the signs a slot L The light-sensitive member F supplies during each revolution of the type cylinder a number of pulses corresponding with the number of signs and the light-sensitive member F supplies one pulse. The controldisc S has two slots L and L which determine the beginning and the end of a line to be printed. The slot L is associated with the first place and the slot L, with the last place. In the space between L and L,,, which corresponds to the voids, the paper is displaced. The accurate position of the light-sensitive member is chosen so that the signal p supplied by F coincides with the signal pg supplied by F of the first sign of the set of signs. The signal from the slot L appears, however, closely after the p signal of the last sign.

The motor drives the type cylinder T, which drives through the worm wheel transmission G the hammer disc H with reduced speed. In the rest position the bistable trigger FFI cuts off the gate U so that the p pulses have no effect. The bistable trigger FFZ is also in zero position, so that the p pulses, having to reset FFZ to zero, remain inoperative. The adjustment of FF2 to zero cuts off the gates U U and U so that neither the 2 pulses nor the shift pulses p in the storage A can become operative. Also the carry pulses p; produced during the arithmetical operation in the last place of the storage a remain inoperative. The printing order P renders FFI conducting. The next-following pulse p.,,, which, as stated above, coincides with the first sign pulse ppasses through the gate U and sets FF2, after which the gates U U and U, are opened (the pulse produced previously by the slot L cannot pass through U since it does not coincide with any p pulse).- At the instant when the p and p, pulses coincide, the hammer k is located opposite the first place and the digit is in front of the printing position. The p pulse raises the content of the first storage place a by 1. If a 9 is found at 'a the resultant carry through the gate U subsequent to amplification in V renders the printing magnet M inoperative, so that the 9 is printed at the first place. Each new sign arriving in the printing position raises by its ppulse the content of a by 1. When at a and 8 is found, first the 8 will be printed and so on. After then ten signs have been covered, a has again the initial value and the slot L supplies a shift pulse p which moves the second place of the storage to the position a After the L voids have been covered, a again receives 10 pulses, which cause printing of the second place in accordance With the content of a After all places of the number have thus been printed, the slot L produces the pulse p which resets FFZ to the initial position. The output voltage pulse resulting therefrom serves as a starting signal for the paper transport and resets FFl to its initial state. If no further printing order follows, no printing is carried out during the further revolution of the type cylinder.

What is claimed is:

1. An electromechanical serial printer comprising a rotatable type cylinder having a plurality of raised characters thereon, a plurality of magnetically controllable hammers, each of said hammers having a striking face, means for advancing a printing material between said hammers and said cylinder, a continuously rotatable hammer carrier, the axis of rotation of said type drum being parallel to the plane of the striking face of a hammer in striking position, said plurality of hammers being arranged on the face of said hammer carrier in a helical array about the axis of rotation of said carrier, a selectively operable magnet, means sequentially rotating said carrier and positioning each of said hammers into striking position between said printing material and said magnet in synchronism with the movement of said type cylinder and means 6 responsive to the position of said type cylinder to selectively actuate said magnet when a desired character is in front of a hammer in striking position.

2. A serial printer as claimed in claim 1, wherein said hammer carrier is formed by a disc, the axis of rotation of which is at right angles to the axis of rotation of the type cylinder.

3. A serial printer as claimed in claim 1, wherein said hammer carrier is formed by a cylinder, the axis of rotation of which is parallel to the axis of rotation of the type cylinder, the hammers being relatively shifted in place at the periphery of said cylinder to form a helical array, said magnet being positioned inside said cylinder.

4-. A serial printer as claimed in claim 1 wherein the lines of characters on the periphery of the type cylinder are positioned at an acute angle to the axis of rotation.

References Cited UNITED STATES PATENTS 2,656,240 10/1953 Hell 178-30 2,689,520 9/1954 Katz 101103 2,757,775 8/ 1956 'Hickerson 1975 1 2,843,243 7/1958 Masterson 197--49 2,874,634 2/ 1959 Hense 10193 2,949,846 8/1960 Hoffman et al. 10193 3,135,195 6/1964 Potter 10193 3,209,682 10/1965 Cooper et al. 101-109 3,212,435 4/1966 Walker 10193 3,247,788 6/1966 Wilkins et a1. 10193 3,256,969 11/1966 Bretti 19750 X 3,282,205 11/1966 Cogar 101-93 WILLIAM B. PENN, Primary Examiner.

Patent No. 3,354,818

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION November 28, 1967 Gerhard Haas It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, line 8, F 35,286" should read P 35,286 Column 1, line 44, "proper" should read itself Column 2, line 50 "cylinder" should read cylinder T Signed and sealed this 18th day of November 1969.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer 

1. AN ELECTROMECHANICAL SERIAL PRINTER COMPRISING A ROTATABLE TYPE CYLINDER HAVING A PLURALITY OF RAISED CHARACTERS THEREON, A PLURALITY OF MAGNETICALLY CONTROLLABLE HAMMERS, EACH OF SAID HAMMERS HAVING A STRIKING FACE, MEANS FOR ADVANCING A PRINTING MATERIAL BETWEEN SAID HAMMERS AND SAID CYLINDER, A CONTINUOUSLY ROTATABLE HAMMER CARRIER, THE AXIS OF ROTATION OF SAID TYPE DRUM BEING PARALLEL TO THE PLANE OF THE STRIKING FACE OF A HAMMER AND STRIKING POSTION, SAID PLURALITY OF HAMMERS BEING ARRANGED ON THE FACE OF SAID HAMMER CARRIER IN A HELICAL ARRAY ABOUT THE AXIS OF ROTATION OF SAID CARRIER, A SELECTIVELY OPERABLE MAGNET, MEANS SEQUENTIALLY ROTATING SAID CARRIER AND POSITIONING EACH OF SAID HAMMERS INTO STRIKING POSITION BETWEEN SAID PRINTING MATERIAL AND SAID MAGNET IN SYNCHRONISM WITH THE MOVEMENT OF SAID TYPE CYLINDER AND MEANS 